a slang word for the word "nothing". It became popular with the movie "Big Lebowski". There is a scene in the movie where Jeff Bridges' character is the victim of a break in by some self described nihilists who proclaim they believe in nothing but because of their German accents they pronounce the word as nussing.
from the Big Lebowski - "We believe in nussing, Lebowski"
slang for the word "done". Used when you have completed or quitting a task. It is also used to describe when you are bored. Nihilists often use this word. It is popular when using this word to spell it out.